Wow… And to think I thought there were just rocks craters and a few crashed lunar probes on the dark side of the moon.
It has long been a theory of some UFOlogists that the far side of the Moon could harbor a base for extraterrestrials. Presuming they come from a distant planet in some other solar system, they must have a base from which they can make their regular visits to the Earth. What better place than the far side of the Moon, which is perpetually hidden from sight?
Of course, i did a little looking around and found other people that think along the same lines.